Based on the configuration below, when a HTTP request arrives at the Mule application's endpoint, the execution order will be A1, B1, F1, B2, A2. This is because policies are executed before and after the API implementation flow according to their order attribute. Policy A has order 1, which means it is executed first before Policy B, which has order 2. The flow is executed after both policies are executed before the flow. Then, Policy B is executed after the flow before Policy A is executed after the flow. Reference: https://docs.mulesoft.com/api-manager/2.x/policies-policy-order

When an HTTP request is received and the HTTP Caching policy is applied first, it checks if there is a cached response for that request in Object Store. If there is a cache hit, meaning that a valid cached response exists, then only the HTTP Caching policy is evaluated and the cached response is returned to the caller without invoking the OAuth policy or the API implementation. If there is a cache miss, meaning that no valid cached response exists, then both the HTTP Caching policy and the OAuth policy are evaluated before invoking the API implementation. Reference: https://docs.mulesoft.com/api-manager/2.x/http-caching-policy#policy-ordering

To communicate asynchronously between two APIs deployed to a two-node on-prem cluster, the developer can use the VM Connector if the two APIs use the same domain. The VM Connector allows passing messages between different Mule applications within a single Mule runtime instance or across different instances using shared memory or persistent storage. If two APIs are deployed under the same domain, they can share resources such as VM queues and communicate asynchronously using VM Connector operations. Reference: https://docs.mulesoft.com/mule-runtime/4.3/vm-connector https://docs.mulesoft.com/mule-runtime/4.3/shared-resources

The MuleSoft recommended method to encrypt sensitive property data is to use the Secure Properties Tool that comes with Anypoint Studio. This tool allows encrypting properties files with a secret key and then decrypting them at runtime using the same key. The encryption key and sensitive data should be different for each environment to ensure security and avoid accidental exposure of sensitive data. Reference: https://docs.mulesoft.com/mule-runtime/4.3/secure-configuration-properties

To encrypt the data before sending it to the backend application using PGP encryption, the application needs the public key from the backend service. PGP encryption uses a public-key cryptography system, which means that each party has a pair of keys: a public key and a private key. The public key is used to encrypt data, and the private key is used to decrypt data. Therefore, to encrypt data for a specific recipient (the backend service), the application needs to use the recipient's public key. The recipient can then use its own private key to decrypt the data. Reference: https://docs.mulesoft.com/mule-runtime/4.3/cryptography-pgp